commanded by the pilot. Any
deviation requires that electric
elevator trim be turned off and
flight conducted using only
Trim disconnect switch - Press
and check that electric trim
disconnects and that ELEV
TRIM light extinguishes (C-
12C, and C-12D), or ELEV
TRIM OFF light illuminates
*8. Autopilot/flight director (AP-106) -
Check as follows:
Since the pressure of airflow that normally
opposes movement of control surfaces is ab-
sent during preflight check, it is possible to
get a hardover control surface deflection if
an autopilot command is allowed to remain
active for any appreciable length of time.
Move turn knob and pitch thumbwheel only
enough to check operation, then return them
to the center position.
a. Flight Director (FD) and Radio
warning flags - Check masked.
b. Heading switch-indicator (Au-
topilot mode selector panel) -
(HSI) - Set heading marker un-
der lubber line.